Mecolaesthus cornutus Huber, 2000

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 73-77

Mecolaesthus cornutus Huber, 2000

Figs 212–214 , 220–228 , 245–247, 254 , 1042

Mecolaesthus cornutus Huber, 2000: 262 , figs 1044–1047 (♂).

Priscula ulai (misidentification) – González-Sponga 1999: 160, figs 74–75 (♀ only; see Note below).

Note

The female of M. cornutus has not been known previously, but numerous males and females newly collected together at various localities (listed below) unambiguously show that the female paratype of Priscula ulai González-Sponga, 1999 is a misidentified M. cornutus .

Diagnosis (amendments; see Huber 2000)

Females are easily distinguished from most known congeners by strongly protruding epigynum longer than wide and posteriorly narrowing ( Figs 245, 254 ); similar only in M. tabay Huber, 2000 , but epigynum in M. tabay rather triangular and smaller (width: ~ 420 µm, vs 580 µm in M. cornutus ). The female of M. azulita Huber, 2000 is unknown.

New records

VENEZUELA – Mérida • 2 ♂♂, 2 ♀♀, ZFMK (Ar 21872), El Valle , forest above road (8.700° N, 71.094° W), 2430 m a.s.l., 25 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 3 ♂♂, 3 ♀♀, ZFMK (Ar 21873), and 3 ♀♀ in pure ethanol, ZFMK (Ven18-219), near Escaguey, NE Mérida (8.6918° N, 70.9950° W), 2220 m a.s.l., 23 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 5 ♂♂, 5 ♀♀, ZFMK (Ar 21874), and 1 ♂, 5 ♀♀ in pure ethanol, ZFMK (Ven18-222), Mucuy , along Laguna El Suero trail (between 8.629° N, 71.039° W and 8.623° N, 71.034° W), 2200–2300 m a.s.l., 24 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 4 ♂♂, 11 ♀♀, ZFMK (Ar 21875–76), and 1 ♂, 4 ♀♀ in pure ethanol, ZFMK (Ven18-230), Monte Zerpa , forest above La Hechicera (8.634° N, 71.163° W – 8.639° N, 71.167° W), 2050–2180 m a.s.l., 26 Nov. 2018 (B.A. Huber, O. Villarreal M., N.A. Sánchez G.) • 1 ♂, ZFMK (Ar 21877), same locality, 14–21 Jun. 2014 (N. Sánchez, M. Fernández) .

Redescription of male (amendments; see Huber 2000)

Eye measurements (male from El Valle): distance PME–PME 160 µm; diameter PME 110 µm; distance PME–ALE 100 µm; distance AME–AME 25 µm; diameter AME 25 µm. Carapace mostly pale gray, only ocular area and anterior margins brown to black ( Fig. 212 ); clypeus also brown; sternum mostly pale gray, with small brown median mark anteriorly including labium; abdomen pale bluish gray, with dark bluish marks dorsally and laterally, lung plates brown, large dark gray mark at gonopore area and dark bluish median mark behind gonopore. Thoracic furrow shallow but distinct; carapace in some males not inflated posteriorly, in other males weakly inflated. Long cheliceral apophyses slightly closer together than shown in the original publication ( Huber 2000: fig. 1044; the apophyses were probably slightly moved by the pressure of the cover slide); distance between tips in three newly studied males: 230–250 µm. Pedipalps, procursus, and genital bulb as in Figs 220–227 . Prolateral trichobothrium present on tibia 1. Tibia 1 in 17 males (including the three males measured in Huber 2000): 5.0–6.5 (mean 5.7).

Description of female

Females in general similar to males ( Fig. 214 ) but dark mark on sternum larger, covering anterior half of sternum. Dark and light rings on legs more distinct. Epigynum ( Figs 245, 254 ) strongly protruding, longer than wide and posteriorly narrowing. Internal genitalia ( Figs 228 , 246–247 ) with strong anterior arc, pair of large pore plates and V-shaped sclerite on ventral wall of uterus externus. Tibia 1 in 19 females: 3.4–4.4 (mean 4.1).

Distribution

Known from several neighboring localities in the Venezuelan state Mérida (Fig. 1042). All localities are at about 2000–2690 m a.s.l.

Natural history

At Escaguey, the spiders were found in small webs in hollow logs on the ground. In Mucuy, this species shared the habitat with several other species of Mecolaesthus , but at different altitudes and in slightly different microhabitats: M. cornutus was found at lower altitude (~ 2200–2300 m a.s.l.) in small cavities in the ground; M. tabay was found at the same altitude but in hollow logs; M. mucuy was found at higher altitude (~ 2500–2700 m a.sl.) and mostly in bromeliads ~ 1–2 m above the ground; M. longipes Huber sp. nov. occupied large sheltered spaces at ~ 2400–2600 m a.s.l.; and M. fallax was found at all altitudes (~ 2200-2700 m a.s.l.) but in a very different microhabitat (undersides of live leaves). Two egg sacs contained approximately 20– 40 eggs.

Figures

Figs 212–219. Mecolaesthus Simon, 1893; live specimens. 212–214. M. cornutus Huber, 2000; male from Mérida, Mucuy, female with egg sac from Mérida, Escaguey. 215. M. cordiformis (González- Sponga, 2009); male from Mérida, forest near La Carbonera. 216–217. M. mucuy Huber, 2000; male and female from Mérida, Mucuy. 218–219. M. tabay Huber, 2000; male and female from Mérida, El Valle.

Figs 220–221. Mecolaesthus cornutus Huber, 2000; from Mérida, El Valle (ZFMK Ar 21872); left male pedipalp, prolateral and retrolateral views. Scale line: 0.5 mm.

Figs 222–228. Mecolaesthus cornutus Huber, 2000; from Mérida, El Valle (ZFMK Ar 21872). 222– 224. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 225–227. Left genital bulb, prolateral, dorsal, and retrolateral views. 228. Cleared female genitalia, dorsal view. Scale lines: 0.5 mm.

Figs 245–256. Mecolaesthus Simon, 1893; epigyna, ventral and lateral views and cleared female genitalia, ventral and dorsal views. 245–247, 254. M. cornutus Huber, 2000; from Mérida, El Valle (ZFMK Ar 21872). 248–250, 255. M. peckorum Huber, 2000; from Mérida, Monte Zerpa (ZFMK Ar 21879). 251–253, 256. M. mucuy Huber, 2000; from Mérida, Mucuy (type locality; ZFMK Ar 21885).